Have you ever wanted to give someone the finger in mediation? Or have you wondered why someone was so aggressive in negotiations. Maybe his finger length will affect both of those questions.

I was researching issues regarding negotiations and found some interesting connections between the finger length and aggressive behavior. Specifically, the ratio between the index finger (digit 2 or 2D) and the ring finger (digit 4 or 4D) plays an important part in negotiations. The reason – testorone levels during the mother’s pregnancy.

Don’t believe me? Have a look yourself at some of the interesting studies relating to finger length.

Dr Jim Golby and Jennifer Meggs from Teesside discovered a connection the 2D:4D ratio and the ability to achieve mental toughness. According to Golby and Meggs, prior research has shown that the 2D:4D ratio (index finger/ring finger) has the potential to explain sporting success. An index finger that is much shorter than the ring finger is caused by exposure to testosterone in the womb.

The results of Golby’s study showed that participants with a higher 2D:4D ratio were more likely to demonstrate mental toughness and have higher levels of sporting achievements. Dr Golby explained: “It appears that high prenatal levels of testosterone may result in increased mental toughness, optimism and hence aptitude towards sport. This provides tentative support for the conclusion that mental toughness may be partially biologically predetermined.”

Another recent study from Utrecht and Cambridge Universities has only now discovered that a dosage of testosterone under the tongue in volunteers negatively affects a person’s ability to empathize. The findings are published in the journal Proceedings of the National Academy of Sciences.

The researchers not only found that administration of testosterone leads to a significant reduction in empathy, but that this the amount of empathy can be calculated by the usage of the 2D:4D digit ratio, a marker of prenatal testosterone. Those men who had the highest ratios had the lowest scores on empathy.

Another study found a connection between testosterone and risky behavior. “Previous studies have linked high testosterone levels with risky behaviour and financial success,” says senior researcher Gad Saad, Concordia University Research Chair in Evolutionary Behavioral Sciences and Darwinian Consumption as well as a marketing professor at the John Molson School of Business. “We investigated the relationship between prenatal testosterone and various risk proclivities. Our findings show an association between high testosterone and risk-taking among males in three domains: recreational, social and financial.”

Finally, and most recently, a new study found that there was a direct link between the size of fingers and negotiating strategies. According to a new study called “Lex talionis: Testosterone and the law of retaliation,” to be published in an upcoming issue of the Journal of Experimental Social Psychology, there is a significant role in pre-natal leveles of testosterone and business negotiations. If someone’s ring finger and his index finger are the same length, there is an increase in pre-natal exposure to testosterone. According to the research, a person who has little difference between the index finger and ring finger is more concerned with preserving his status and saving face. Unless you handle his ego with kid gloves, he will be quick to take offense.

And second, if you cross him, he will retaliate. Specifically, when those people were put in situations where they felt that they had either been cheated or lost in the negotiation, they made every effort to retaliate against the negotiating partner.

“Testosterone is a hormone associated with status-seeking and a need to save face,” notes Adam Galinsky, the Kellogg professor who co-wrote the study. “It makes a powerful difference in how people respond to situations.

“People with low testosterone — that is, with a noticeable difference in the length of their second and fourth digits — may perceive that they’re being treated unfairly, but they’re likely to go sulk in a corner.”

However, Galinsky says, “If you’re looking across a bargaining table at someone who has a slight difference, or no difference, between the second and fourth digits, be careful.” Make an extra effort to mollify that person and stroke his ego, because doing otherwise is “like slapping a sleeping tiger.”

So who would have thought that there was a such a connection between testosterone and negotiations. But there is.